The present invention relates generally to the processes for manufacture of fibrous insulation products, and more particularly, to biocides or biocidal agents useful for killing unwanted organisms associated with bio-based binders in manufacturing fiberglass insulation products.
Conventional fibers are useful in a variety of applications including reinforcements, textiles, and acoustical and thermal insulation materials. Although mineral fibers (e.g., glass fibers) are typically used in insulation products and non-woven mats, depending on the particular application, organic fibers such as polypropylene, polyester, and multi-component fibers may be used alone or in combination with mineral fibers in forming the insulation product or non-woven mat.
Fibrous glass insulation products generally comprise randomly-oriented glass fibers bonded together by a cured thermosetting polymeric material. Molten streams of glass are drawn into fibers of random lengths and blown into a forming chamber or hood where they are randomly deposited as a pack onto a moving conveyor or chain. The fibers, while in transit in the forming chamber and while still hot from the drawing operation, are sprayed with an aqueous dispersion or solution of binder. The residual heat from the glass fibers and from the flow of hot gases during the forming operation are sufficient to vaporize much of the water from the binder, thereby concentrating the binder dispersion and depositing binder on the fibers as a viscous liquid with high solids content. Sufficient binder is applied and cured so that the fibrous blanket can be compressed for packaging, storage and shipping, yet regains its thickness—a process known as “loft recovery”—when installed, e.g. in the insulation cavities of buildings. The binder composition also provides protection to the fibers from interfilament abrasion and promotes compatibility between the individual fibers.
The uncured fibrous pack is transferred to a curing oven where a gas, heated air for example, is blown through the pack to remove moisture, cure the binder and rigidly bond the glass fibers together in a three-dimensional structure known as a “blanket” with a desired thickness. After the binder has cured, the fiber insulation may be cut into lengths to form individual insulation products, and the insulation products may be packaged for shipping to customer locations. One typical insulation product produced is an insulation batt or blanket, which is suitable for use as wall insulation in residential dwellings or as insulation in the attic and floor insulation cavities in buildings. Another common insulation product is air-blown or loose-fill insulation, which is suitable for use as sidewall and attic insulation in residential and commercial buildings as well as in any hard-to-reach locations. Loose-fill insulation may be formed of small cubes that are cut from insulation blankets, compressed, and packaged in bags.
Historically, binders have been phenolic-formaldehyde resins, although more recently attempts have been made to reduce undesirable formaldehyde emissions from formaldehyde-based resins. Such approaches have included formaldehyde scavengers such as ammonia and urea, but these introduce other problems. In addition, some have focused on the use of polyacrylic acid with a polyhydroxyl crosslinking agent. See, for example, the polyacrylic acid/polyol/polyacid acid binder system described in U.S. Pat. Nos. 6,884,849 and 6,699,945 to Chen, et al.; and the binder chemistry disclosed in U.S. Pat. Nos. 7,258,802 and 7,780,858 to Miks.
In view of the existing problems with current binders, there remains a need in the art for a binder system that is not petroleum dependent, has no added formaldehyde, is bio-based and environmentally friendly, and is cost competitive.